Hi.. First I've installed widget but not the blog. Subsequently I've deleted widget and now I try to install BLOG 0.1 but I can't do it. There is an error. The server say:

"Warning: Cannot modify header information - headers already sent by (output started at C:\wamp\www\silverstripe-v2.2.2\silverstripe-v2.2.2\blog\code\BlogEntry.php:52) in C:\wamp\www\silverstripe-v2.2.2\silverstripe-v2.2.2\sapphire\core\Debug.php on line 151

Error
The website server has not been able to respond to your request."

How can I do for install Blog and widget?

Thank you..

Did you do a db/build?flush=1 after installation?

Yes, I do. When I run /db/build/?flush=1 I read that written

Error
The website server has not been able to respond to your request

Is the standard generic error. It might help to put the site into dev mode which will output the actual error message.

Add this to your mysite/_config.php file

Director::set_environment_type("dev");

I've tried do modify it. I've tried besides to delete the written

Director::set_dev_servers(array(
'localhost',
'127.0.0.1',
));

with the written

Director::set_environment_type("dev");

and the result is the same. It appears:

FATAL ERROR: Bad class to singleton() - BlogEntry
At line 85 in C:\wamp\www\silverstripe-v2.2.2\silverstripe-v2.2.2\sapphire\core\Core.php

user_error(Bad class to singleton() - BlogEntry,256)
line 85 of Core.php

singleton(BlogEntry)
line 175 of DatabaseAdmin.php

DatabaseAdmin->doBuild()
line 90 of DatabaseAdmin.php

DatabaseAdmin->build(Array)
line 261 of Controller.php

Controller->run(Array)
line 104 of Director.php

Director::direct(/db/build/)
line 158 of main.php

Context

--------------------------------------------------------------------------------

Debug (Debug::showError() in line 180 of Debug.php)
className =
BlogEntry
_SINGLETONS =
Member =
Database record: Member
ID :
0
Newsletter =
Database record: Newsletter
ID :
0
Newsletter_SentRecipient =
Database record: Newsletter_SentRecipient
ID :
0
Newsletter_Recipient =
Database record: Newsletter_Recipient
ID :
0
NewsletterType =
Database record: NewsletterType
ID :
0
PageComment =
Database record: PageComment
ID :
0
Post =
Database record: Post
ID :
0
Post_Subscription =
Database record: Post_Subscription
ID :
0
GalleryPage_Extension =
Database record: GalleryPage_Extension
ID :
0
MemberLocation =
Database record: MemberLocation
ID :
0
Email_BounceRecord =
Database record: Email_BounceRecord
ID :
0
Email_BlackList =
Database record: Email_BlackList
ID :
0
PageView =
Database record: PageView
ID :
0
SiteTree =
Database record: SiteTree
ID :
0
Translatable = Translatable::__set_state(array( 'translatableFields' => array ( 0 => NULL, 1 => true, 2 => NULL, 3 => NULL, 4 => NULL, 5 => NULL, 6 => NULL, 7 => NULL, 8 => NULL, ), 'original_values' => NULL, 'owner' => NULL, 'extension_instances' => array ( ), 'class' => 'Translatable', ))
QueuedEmail =
Database record: QueuedEmail
ID :
0
File =
Database record: File
ID :
0
EditableCheckboxOption =
Database record: EditableCheckboxOption
ID :
0
EditableDropdownOption =
Database record: EditableDropdownOption
ID :
0
EditableFormField =
Database record: EditableFormField
ID :
0
EditableRadioOption =
Database record: EditableRadioOption
ID :
0
SubmittedForm =
Database record: SubmittedForm
ID :
0
SubmittedFormField =
Database record: SubmittedFormField
ID :
0
Group =
Database record: Group
ID :
0
Member_UnsubscribeRecord =
Database record: Member_UnsubscribeRecord
ID :
0
Permission =
Database record: Permission
ID :
0
Widget =
Database record: Widget
ID :
0
WidgetArea =
Database record: WidgetArea
ID :
0
Page =
Database record: Page
ID :
0
GhostPage =
Database record: GhostPage
ID :
0

that means it cant find the blog entry php code. You might need to open blog/code/BlogEntry.php and make sure at the top of the file there is a <?php rather then just <? - this is normally the other problem

I've tried to do it but there is a new message that says me there is an error in the first line. I've already tried to insert your written at the top but this time into the pre-existent inverted comma. In this case there is the usual error. I think there is an error becaouse first I've installed widget and after blog. Now I've deleted widget but I can't install blog!